The present invention relates to miniature magnetic heads, and more particularly to a miniature magnetic head installed in a disk storage using a flexible magnetic disk.
FIG. 1 shows an internal plane view of a conventional disk storage which uses a flexible magnetic disk, and FIG. 2 shows a longitudinal section taken along a line II--II shown in FIG. 1. The disk storage comprises a turn table 15, driven and rotated by a driving motor (not shown), on which a flexible magnetic disk 14 as a recording medium for recording data is to be fixed. The disk storage 15 further comprises conventional magnetic heads 2-1 and 2-2 which hold the magnetic disk fixed on the turn table 15. The disk storage still further comprises a head carriage 11 comprising a head carriage body 12 and an upper arm 13 to which the magnetic head 2-1 is attached. FIG. 3 is a perspective view showing the magnetic heads 2-1 and 2-2. Since each of gimbal springs to which the respective magnetic heads 2-1 and 2-2 are attached has substantially the same construction, a magnetic head 2 generalizes both of the magnetic heads 2-1 and 2-2 and a gimbal spring 1 generalizes the above gimbal springs. The magnetic head 2 has first and second ceramic sliders 3 and 4, a tunnel-erase type of magnetic core part 5, and coils 6 and 7 (not shown) each of which is wound around the magnetic core part 5 at a predetermined position. The magnetic head core part 5 is a so-called bulk type magnetic head made by junctioning a ferrite core, and the first and second sliders 3 and 4 are provided at both sides thereof. The magnetic head core part 5 is fixed on the gimbal spring 1 by the sliders 3 and 4. FIG. 4, an enlarged view of the vicinity of a gap of the magnetic core part 5 shown in FIG. 3, shows a read/write magnetic gap 8 (abbreviated R/W gap hereinafter) and erase gaps (abbreviated E gap hereinafter) 9 and 10.
As a disk storage as thin as possible has recently been required, a magnetic head 2 as miniature and thin as possible has been increasingly required. A description will be given of the miniature magnetic head with reference to FIGS. 5 6A and 6B. The magnetic head 2 is attached, as shown in FIG. 5, to the head carriage 11. That is, the magnetic heads 2-1 and 2-2 are respectively attached to the upper arm 13 which is rotatably engaged with the head carriage 12. As is generally known, when data is written down on the magnetic disk 14 (depicted by the one-dot line in FIG. 5) and/or read out therefrom, the upper arm 13 rotates counterclockwise along an arrow X around a rotating center O to contact the magnetic disk 14. Thus, the pair of magnetic head 2-1 and 2-2 contact the magnetic disk 14 to hold it and the writing/reading is performed thereby. On the other hand, when the magnetic disk 14 is ejected from the disk storage, the upper arm 13 is upwardly moved by a mechanism (not shown) to be separated from the disk 14. Then, the magnetic disk 14 is separated from the turn table 15 and ejected from the disk storage. FIG. 5 shows the disk storage in which the upper arm 13 has been upwardly moved. A distance which the upper arm 13 can upwardly move, referred to as an upward moving amount hereinafter, influences how thick the disk storage. That is, the smaller the upward moving amount is, the thinner the disk storage can be made.
FIGS. 6A and 6B respectively show views for explaining a relationship between the size of the magnetic disk and a change in the upward moving amount of the upper arm 13. FIG. 6A depicts the larger magnetic heads 2A-1 and 2A-2, and FIG. 6B depicts the smaller magnetic heads 2B-1 and 2B-2. A description will now be given of a separating operation of the magnetic heads 2A-1 and 2B-1 when the upper arm 13 moves upwardly. First the magnetic heads 2A-1 and 2B-1 are separated from the magnetic disk 14 at an outer position shown by an arrow A and finally at an inner position shown by an arrow B. In this case, the upward moving amount of the upper arm 13 while the magnetic heads 2A-1 and 2B-1 are contacting the magnetic disk and then separate therefrom changes as follows. That is, the upward moving amount of the upper arm 13 having the magnetic head 2A-1 is longer than that of the upper arm 13 having the magnetic 2B-1. In other words, if the smaller magnetic head 2B-1 is used, the upward moving amount of the upper arm 13 can be made smaller and thus the disk storage can be made thinner.
The conventional disk storage has a disadvantage in that, since the conventional magnetic head 2 shown in FIG. 3 includes the first and second sliders 3 and 4, the size of the magnetic head 2 becomes relatively large. As a result, the upper arm 13 must move to a higher position in order to separate the magnetic head 2 from the magnetic disk 14 and thus the disk storage cannot be made thinner.